A compound of formula (I): ** Formula ** in which: A is>； = C (H) - or>； = N-； R1 is -N (R2) R3, -N (R2) C (O) R3 or -N (R2) -R4-C (O) OR3； or R1 is an N-heterocyclyl optionally substituted with one or more substituents selected from the group consisting of halo and -R4-C (O) OR2； each R2 and R3 is hydrogen, alkyl, alkenyl, optionally substituted aralkyl, optionally substituted cycloalkyl, optionally substituted cycloalkylalkyl and optionally substituted heteroarylalkyl； and each R4 is independently selected from the group consisting of a direct bond and an optionally substituted linear or branched alkylene chain； as an isolated stereoisomer or mixture thereof, or a pharmaceutically acceptable salt thereof； with the proviso that the compound of formula (I) is not a compound selected from the group consisting of: 1 - ((6,7-dihydro-5H-benzo [6,7] cyclohepta [1,2-c] pyridazin -3-yl) -N3- (7- (pyrrolidin-1-yl) -6,7,8,9-tetrahydro-5Hbenzo [7] anulen-2-yl) -1H-1,2,4-triazole- 3,5-diamine； 1 - ((6,7-dihydro-5H-benzo [6,7] cyclohepta [1,2-c] pyridazin-3-yl) -N3- (7 - ((bicyclo [2, 2,1] heptan-2-yl) amino) -6,7,8,9-tetrahydro-5H-benzo [7] anulen-2-yl) -1H-1,2,4-triazol-3,5- diamine； 1 - ((6,7-dihydro-5H-benzo [6,7] cyclohepta [1,2-c] pyridazin-3-yl) -N3- (7 - ((bicyclo [2,2,1]) heptan-2-yl) (methyl) amino) -6,7,8,9-tetrahydro-5H-benzo [7] anulen-2-yl) -1H-1,2,4-triazol-3,5-diamine ； 1 - ((6,7-dihydro-5H-benzo [6,7] cyclohepta [1,2-c] pyridazin-3-yl) -N3 - ((7-piperidin-1-yl) -6.7 , 8,9-tetrahydro-5Hbenzo [7] anulen-2-yl) -1H-1,2,4-triazol-3,5-diamine； 1- ((6,7-dihydro-5H-benzo [6, 7] cyclohepta [1,2-c] pyridazin-3-yl) -N3 - ((7-azetidin-1-yl) -6,7,8,9-tetrahydro-5H-benzo [7] nullify 2- il) -1H-1,2,4-triazol-3,5-diamine； 1 - ((6,7-dihydro-5H-benzo [6,7] cyclohepta [1,2-c] piri dazin-3-yl) -N3 - ((7- (R) -pyrrolidin-1-yl) -6,7,8,9-tetrahydro-5Hbenzo [7] anulen-2-yl) -1H-1,2 , 4-triazol-3,5-diamine； and 1 - ((6,7-dihydro-5H-benzo [6,7] cyclohepta [1,2-c] pyridazin-3-yl) -N3
